Conventional designs for WCDMA receivers in handsets or local area base stations that meet the 3GPP TS25.101 standard include an external inter-stage filter between the low-noise amplifier (LNA) and the mixer for Class I through Class VI devices. These designs for WCDMA handset and base station receivers become unattractive in multi-band applications due to numerous external filter requirements and complex ASIC pin-outs. More external components also require additional printed circuit board (PCB) space. In addition, the use of higher external component count reduces flexibility and configurability of the receiver.
Recently, a receiver architecture was designed that allowed a WCDMA receiver to meet the 3GPP TS25.101 standard without the use of an external inter-stage filter between the LNA and the mixer, as described in U.S. patent application Ser. No. 11/197,017 incorporated by reference above. This receiver architecture uses a three-step gain LNA and a mixer without an intervening external filter.